1. DNA Transcription & Protein Translation

2. Today’s Objectives Introduce Protein Synthesis Compare types of nucleic acid

4. RNA-ribonucleic acid Uses the information from DNA to synthesis proteins.

5. 3 Main Differences from DNA 1. RNA has one strand of nucleotides 2. RNA has ribose as it’s sugar 3. RNA has Uracil as a nitrogen base instead of thymine (U bonds with A)

6. Three Classes of RNA Messenger RNA mRNA Carries the “blueprint” for protein assembly to the ribosome

8. Ribosomal RNA rRNA-combines proteins to form ribosomes upon which polypeptides are assembled

9. Transfer RNA tRNA Brings the correct amino acid to the ribosome and pairs up a mRNA code for that amino acid

10. Codon-A series of 3 bases that code for an amino acid Located on the mRNA strand Anti-Codon-a triplet of nucleotides in transfer RNA that is complementary to the codon in messenger RNA which specifies the amino acid Located on the tRNA molecule

12. DNA Transcription DNA must be copied to messenger RNA (mRNA) mRNA goes from nucleus to the ribosomes in cytoplasm mRNA complements known as codons – Only 3 nucleotide “letters” long Remember RNA has uracil (U) instead of thymine (T)!

13. Transcription – Step I A C G T A T C G C G T A T G C A T A G C G C A T Template DNA Strands

14. Transcription – Step II A C G T A T C G C G T A U G C A U A G C G C A U Template DNA is Matched Up with Complementary mRNA Sequences

15. Transcription Reminders The template strand is the DNA strand being copied The rRNA strand is the same as the DNA strand except Us have replaced Ts

16. Protein Translation Modified genetic code is “translated” into proteins Codon code is specific, but redundant! – 20 amino acids – 64 triplet (codon) combinations

17. Using the Codon Table learn how to use a codon table to translate mRNA into its associated amino acids Let’s Play Bingo!!

18. tRNA in cytoplasm has a codon attached to an amino acid

19. tRNA structure 3-base code (triplet) is an “anticodon” Protein molecule Attached amino acid that is carried from cytoplasm to ribosomes

20. Protein Synthesis Start: Ribosome binds to mRNA at start codon (AUG) Elongation: – tRNA complexes bind to mRNA codon by forming complementary base pairs with the tRNA anticodon – The ribosome moves from codon to codon along the mRNA. – Amino acids are added one by one Release: release factor binds to the stop codon

22. Transcription – Step III mRNA leaves nucleus and goes to ribosomes U G C A U A G C G C A U A new complementary RNA strand is made (rRNA) A C G U A U C G C G U A